PORTLAND — Wondering what the words “TWO DROP” flashing on the Time & Temperature building’s sign mean?

The message refers to the two drops of polio vaccine each child in developing countries receive as part of Rotary International’s effort to eradicate polio, Rotary International District 7780 Governor Ann Lee Hussey.

The display is part of a larger effort by Rotary clubs around the world, marking the humanitarian service organization’s 106th anniversary and promoting their mission to end polio. Buildings around the world, including the New York Stock Exchange, the KPT Government Building in Karachi, Pakistan, the Dutch Parliament Building in The Hague, The Netherlands, as well as Maine’s own Portland Museum of Art have been turned into canvases to spread the organization’s message.

“These global illuminations carry Rotary’s pledge to end polio –  saying to the world that we will fight this crippling disease to the end,” Hussey said. “It is our hope that people worldwide will see this visible pledge and join Rotary and its partners in this historic effort to rid the world of polio forever.”

Tonight and Sunday are the last days the words “End Polio Now” will illuminate the Portland Museum of Art starting at 5:30 p.m.

Rotary International District 7780, which includes 41 clubs from Bethel to Boothbay Harbor south through coastal New Hampshire and northern Massachusetts, selected Portland for this display because of its centralized location and large population, Hussey said.

The week-long awareness effort ends in Portland Sunday with a fundraiser night at the Red Claws game versus the Rio Grande Valley Vipers starting at 5 p.m. at the Portland Expo Building.

Since 1988, great progress has been made in the eradication of polio, Hussey said. There were 350,000 cases reported in 1988. That number has dropped to fewer than 1,000 in 2010.

For more information on Rotary International’s efforts to end polio now, visit www.rotary.org/endpolio and for information on Rotary International District 7780, visit www.rotary7780.org.